ValueProviderWrapper.cs source code in C# .NET

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Code:

                         / DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Core / MS / Internal / Automation / ValueProviderWrapper.cs / 1 / ValueProviderWrapper.cs
                        

                        
                            //---------------------------------------------------------------------------- 
//
// 
//    Copyright (C) Microsoft Corporation.  All rights reserved.
//  
//
// 
// Description: Value pattern provider wrapper for WCP 
//
// History: 
//  07/21/2003 : [....] Ported to WCP
//
//---------------------------------------------------------------------------
 
using System;
using System.Windows.Threading; 
 
using System.Windows.Media;
using System.Windows.Automation; 
using System.Windows.Automation.Provider;
using System.Windows.Automation.Peers;

namespace MS.Internal.Automation 
{
    // Automation/WCP Wrapper class: Implements that UIAutomation I...Provider 
    // interface, and calls through to a WCP AutomationPeer which implements the corresponding 
    // I...Provider inteface. Marshalls the call from the RPC thread onto the
    // target AutomationPeer's context. 
    //
    // Class has two major parts to it:
    // * Implementation of the I...Provider, which uses Dispatcher.Invoke
    //   to call a private method (lives in second half of the class) via a delegate, 
    //   if necessary, packages any params into an object param. Return type of Invoke
    //   must be cast from object to appropriate type. 
    // * private methods - one for each interface entry point - which get called back 
    //   on the right context. These call through to the peer that's actually
    //   implenting the I...Provider version of the interface. 
    internal class ValueProviderWrapper: MarshalByRefObject, IValueProvider
    {
        //-----------------------------------------------------
        // 
        //  Constructors
        // 
        //----------------------------------------------------- 

        #region Constructors 

        private ValueProviderWrapper( AutomationPeer peer, IValueProvider iface )
        {
            _peer = peer; 
            _iface = iface;
        } 
 
        #endregion Constructors
 

        //------------------------------------------------------
        //
        //  Interface IValueProvider 
        //
        //----------------------------------------------------- 
 
        #region Interface IValueProvider
 
        public void SetValue( string val )
        {
            ElementUtil.Invoke( _peer, new DispatcherOperationCallback( SetValueInternal ), val );
        } 

        public string Value 
        { 
            get
            { 
                return (string) ElementUtil.Invoke( _peer, new DispatcherOperationCallback( GetValue ), null );
            }
        }
 
        public bool IsReadOnly
        { 
            get 
            {
                return (bool) ElementUtil.Invoke( _peer, new DispatcherOperationCallback( GetIsReadOnly ), null ); 
            }
        }

        #endregion Interface IValueProvider 

 
        //------------------------------------------------------ 
        //
        //  Internal Methods 
        //
        //------------------------------------------------------

        #region Internal Methods 

        internal static object Wrap( AutomationPeer peer, object iface ) 
        { 
            return new ValueProviderWrapper( peer, (IValueProvider) iface );
        } 

        #endregion Internal Methods

        //----------------------------------------------------- 
        //
        //  Private Methods 
        // 
        //------------------------------------------------------
 
        #region Private Methods

        private object SetValueInternal( object arg )
        { 
            _iface.SetValue( (string)arg );
            return null; 
        } 

        private object GetValue( object unused ) 
        {
            return _iface.Value;
        }
 
        private object GetIsReadOnly( object unused )
        { 
            return _iface.IsReadOnly; 
        }
 
        #endregion Private Methods


        //----------------------------------------------------- 
        //
        //  Private Fields 
        // 
        //-----------------------------------------------------
 
        #region Private Fields

        private AutomationPeer _peer;
        private IValueProvider _iface; 

        #endregion Private Fields 
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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